Various catalysts have been tested for conversion and upgrading of liquid and solid fuels. Among them molybdenum sulfide-based catalysts are widely used for hydroprocessing and hydrodesulfurization. Mo sulfide can be prepared from molybdate or thiomolybdate. A well-established method for preparing MoS2 catalyst involves decomposition of ammonium tetrathiomolybdate (ATTM) in an inert gas or in H2. The MoS2 catalyst generated from decomposition of ATTM is more active than that from sulfidation of molybdenum oxide or the reagent MOS2, and thus ATTM has been used as catalyst precursor for generation of active. The surface area values for thus-prepared MoS2 catalysts are relatively low. Usually somewhere between 6-70 m2/g. It is desirable to have a MoS2 catalysts with higher surface area values than currently available. It is also desirable to have a MoS2 catalysts that is more active than currently available.
The present invention is a new and simple method of decomposing ammonium tetrathiomolybdate (ATTM) in an organic solvent with added water under H2 pressure. Model compound reactions of 4-(1-naphthylmethyl)bibenzyl (NMBB) were carried out at 350-425xc2x0 C. under H2 pressure in order to examine the activity of the Mo sulfide catalysts generated from ATTM with and without added water for Cxe2x80x94C bond cleavage and hydrogenation of aromatic ring. The Mo sulfide catalysts generated from ATTM with added water were much more effective for Cxe2x80x94C bond cleavage and hydrogenation of aromatic moieties at 350-425xc2x0 C. than those from ATTM alone. Two-step tests revealed that the addition of water is effective for generating highly active Mo sulfide catalyst from ATTM, but water itself does not promote catalytic conversion. Removal of water after the decomposition of ATTM with added water at 350-400xc2x0 C. under H2 pressure by hot purging gives highly active Mo sulfide catalyst.